Don't know how official this is or if it is purposeful misdirection for the up coming Christmas Special.
"As if the "Doctor Who" regeneration mystery couldn't get more difficult to follow, showrunner Steven Moffat is talking again -- and he's making matters even more confusing.
While speaking to the Radio Times, Moffat says that Matt Smith is the 13th and final Doctor, after counting John Hurt's War Doctor and David Tennant using up one of the regenerations during his stint.
That makes Smith regenerating into Peter Capaldi during the Christmas special a bit problematic, because the Doctor doesn't have any lives left. "The 12 regenerations limit is a central part of 'Doctor Who' mythology -- science fiction is all about rules, you can't just casually break them," Moffat says. How another Doctor will fit in there is anyone's guess.
According to the Radio Times, Smith's Doctor will give a speech about "dying" during the Christmas special. Perhaps if the Doctor dies after his final regeneration, and is brought back to life, he gets to start over from scratch?
Any other show could easily just ignore this sort of limitation, but Moffat won't stop talking about it, so he must have a pretty clever loophole to introduce Capaldi. It won't take long to find out exactly that that is, as the "Doctor Who" Christmas special airs at 9 p.m. ET Dec. 25 on BBC America."
This years Christmas ep looks to be shaping up to very interesting.
"Jenkins! Chap with the wings there...five rounds rapid."
Didn't Moffat in another interview also confirm that River gave the Doctor her regenerations?
I don't think I've read the interview you mention. But I've never taken it that the Doctor gained the regenerations that River gave up to save his life in Let's Kill Hitler. I've always assumed that she used the energy of her unused regenerations to somehow counteract the poison.
I'm predicting that the Doctor won't have enough energy left to regenerate after all that magic hand faffery and healing River's wrist, so he will temporarily become the Valeyard (in the time between his twelfth and thirteenth incarnation, as mentioned in Trial of a Timelord) and go on a ruthless quest to get more lives, which is the terrible event that the Silence have been trying to stop.
"There are worlds out there where the sky is burning, and the sea's asleep, and the rivers dream; people made of smoke and cities made of song. Somewhere there's danger, somewhere there's injustice, somewhere else the tea's getting cold. Come on, Ace. We've got work to do."
Moffat is very clever, more so than many people give him credit for. He explains things, but often not directly. Anyway, I don't worry about the regeneration limit; it was established as being breakable in the first story it was mentioned in.